The Deputy Prime Minister insisted he took immediate action after learning of ‘appalling’ sexual allegations against the former Lib Dem MP.

He spoke out after criticism that he failed to act for three years after first being told of claims against Mr Hancock, 67, from a female constituent.

The Portsmouth South MP was suspended from the party this week after the leaking of a QC’s report into claims - which he denies - of inappropriate behaviour towards a woman who has mental health issues.

The married MP had already resigned the parliamentary party whip last year, but was still sitting as a Lib Dem local councillor.

Mr Clegg, who also faces criticism over the handling of separate sexual harassment allegations against Lord Rennard, said he had acted last year as soon as he heard that a civil case was being brought against the MP.

He said today: “When I was given the specific allegations at the beginning of last year I immediately asked our chief whip to investigate.

“When those allegations were then supported by the QC’s report that has come to light this week again we acted immediately and Mike Hancock has been suspended from the Lib Dems altogether.”

The Deputy Prime Minister added: “The first time I was given specific allegations was when there was a notification of legal proceedings, which I was informed of at the beginning of last year.

“You can only react to things that are put to you.

“That is when I acted. I acted immediately because I was as appalled as anyone by the seriousness of these allegations.”

Portsmouth City Council had asked Nigel Pascoe QC to investigate whether Mr Hancock had breached the council’s code of conduct after a Hampshire Police investigation concluded there was no case to answer.

However the authority has put its investigation on hold until the outcome of the civil court action.

Tonight it has emerged that Mr Hancock’s alleged victim has won a bid to force Portsmouth City Council to make the QC’s full report available to her as part of that planned action.

The council opposed the application for full disclosure of the report - a redacted version of which has already been leaked to the public.

But Master Leslie, a High Court official, ruled disclosure was necessary so that the woman could feel she had “a fair hearing and a fair crack of the whip”.

The report, carried out by Nigel Pascoe QC for the council, found “compelling” evidence of “serious and unwelcome sexual behaviour” towards a vulnerable woman constituent.

She suffered a mental health disorder and had been sexually abused as a child.

Today the woman’s solicitor, Harriet Wistrich, said it had taken the Lib Dem leadership three years to take action after the complaints about his conduct first came to light.

She said: “There seems to be a pattern here of Lib Dems not dealing with the matter.

“My client’s wish is for him to be held properly to account for his misconduct. We are exploring all avenues.

‘It has taken us three years to reach this stage because every time she has gone down one regulatory procedure or another, there’s been no investigation or no decision made.

“I think that the Lib Dems have very belatedly suspended him from party membership.

“The council have been appalling in not taking action earlier.

“He still is a councillor, they could proceed now with the allegations that he has breached their council code of conduct.”

Local Lib Dems in Portsmouth have continued to voice support for Mr Hancock accusing the party leadership of suspending him without due process.

Simon Dodd, chairman of Portsmouth Lib Dems, said: “We believe in proper and due process and that as there is an ongoing court case, it is the court that should rule first, having considered all the evidence, not the media or internal panels.

“Mike Hancock has loyally represented the people of Portsmouth for over 40 years and he will continue to serve as an excellent constituency MP and as a councillor.”

Today Mr Hancock refused to comment on his future after chairing a meeting of a city council committee.

He said: “I’m not saying anything more. I’m not having a running commentary with the press because that would be inappropriate.”

Mr Hancock was also asked about his future as chairman of the committee meeting he had just chaired.

He said: “No, that is all you are going to get. I’m sorry.”

Mr Hancock had been chairing the “cabinet member for planning, regeneration, and economic development meeting” at the city’s Guildhall.

He also refused to answer if he would attend a meeting of the city’s Liberal Democrat meeting tonight.

Mr Hancock’s alleged victim has claimed that he exposed himself to her and made unwanted sexual advances to her and that she was left feeling suicidal by his behaviour.

The allegation has twice been investigated by police, initially in 2010, and repeatedly denied by Mr Hancock.

Officers and the CPS decided there was not enough evidence to pursue a case against him.